This invention relates generally to re-entrant type horn loudspeakers and more particularly, it relates to a dual diverging manifold loudspeaker system having a unique configuration which produces acoustic pressure levels at least equivalent to that of conventional horn loudspeakers while being smaller and more compact than those traditionally available.
As is generally known to those in the art of high power emergency-warning loudspeaker systems, there is employed typically a compression driver assembly of high power and efficiency which is coupled to a special re-entrant type of horn. Due to space limitations in the emergency-warning loudspeaker industry, the re-entrant type of horn is commonly utilized in which the horn sections "fold" back on itself rather than the use of "straight" horn elements as in the non-emergency loudspeaker field. However, such re-entrant type of horn loudspeakers suffer from the disadvantage of inadequate thermal or heat transfer when combined with an additional housing. As a result, there was a severe limitation on the amount of area where other components and housings could be located near the loudspeaker.
Further, in conventional loudspeaker designs the compression driver assembly is usually mounted behind the re-entrant type of horn so as to face the throat of the horn. Thus, these existing loudspeaker designs were very inefficient in their utilization of space when placed in other housings since the driver assembly would be protruding from the rear of the horn. Also, the prior art loudspeaker designs offer little or no protection from the outside environment for the compression driver assembly without the use of additional housings, thereby increasing materials cost and labor.
A diagrammatic view of a conventional loudspeaker system of the double re-entrant type is illustrated in FIG. 1 and has been labeled "Prior Art." The loudspeaker system is designated generally by reference numeral 10 and is comprised of a compression driver assembly 12 which is mounted behind a horn 14 adjacent a throat 16. A planar sound wave generated by a vibrating diaphragm (not shown) located inside the driver assembly 12 is transmitted from the throat 16 to the mouth 18 by means of a first sound passageway 20 of a circular or conical shape. The sound wave impinges on the tip surfaces 22 of a conical-shaped member 24 and is then reflected back down second annular sound passageways 26 of the member 24. The planar sound waves are expanded exponentially in the areas 26 as they approach the throat 30. The surfaces 32 reflect the sound waves forward and toward the mouth 34 and to the outside atmosphere 36.
It would therefore be desirable to provide an improved loudspeaker system for generating equivalent sound pressure levels of existing loudspeaker systems while occupying much less space and providing good thermal transfer to the surrounding ambient atmosphere. The dual diverging manifold loudspeaker system of the present invention represents an improvement over the existing prior art designs. The present loudspeaker system includes a generally cubically-shaped outer horn housing and an inner dome-like cap member for encapsulating therebetween a conventional compression driver assembly.